Context The long-term renal prognosis of patients with diarrhea-associated hemolytic
uremic syndrome (HUS) remains controversial.
Objectives To quantify the long-term renal prognosis of patients with diarrhea-associated
HUS and to identify reasons for different estimates provided in the literature.
Data Sources We searched MEDLINE and Experta Medica (EMBASE) bibliographic databases
and conference proceedings, and we contacted experts until February 2003.
We also searched the Institute for Scientific Information index and reference
lists of all studies that fulfilled our eligibility criteria. The search strategy
included the terms hemolytic-uremic syndrome, purpura, thrombotic thrombocytopenic, Escherichia coli O157, longitudinal studies, kidney diseases, hypertension, and proteinuria
Study Selection Any study that followed up 10 or more patients with primary diarrhea-associated
HUS for at least 1 year for renal sequelae.
Data Extraction Two authors independently abstracted data on study and patient characteristics,
renal measures, outcomes, and prognostic features. Disagreements were resolved
by a third author or by consensus.
Data Synthesis Forty-nine studies of 3476 patients with a mean follow-up of 4.4 years
(range, 1-22 years at last follow-up) from 18 countries, 1950 to 2001, were
summarized. At the time of recruitment, patients were aged 1 month to 18 years.
In the different studies, death or permanent end-stage renal disease (ESRD)
ranged from 0% to 30%, with a pooled incidence of 12% (95% confidence interval
[CI], 10%-15%). A glomerular filtration rate lower than 80 mL/min per 1.73
m2, hypertension, or proteinuria was extremely variable and ranged
from 0% to 64%, with a pooled incidence of 25% (95% CI, 20%-30%). A higher
severity of acute illness was strongly associated with worse long-term prognosis.
Studies with a higher proportion of patients with central nervous system symptoms
(coma, seizures, or stroke) had a higher proportion of patients who died or
developed permanent ESRD at follow-up (explaining 44% of the between-study
variability, P = .01). Studies with a greater proportion
of patients lost to follow-up also described a worse prognosis (P = .001) because these patients were typically healthier than those
followed up. One or more years after diarrhea-associated HUS, patients with
a predicted creatinine clearance higher than 80 mL/min per 1.73 m2,
no overt proteinuria, and no hypertension appeared to have an excellent prognosis.
Conclusions Death or ESRD occurs in about 12% of patients with diarrhea-associated
HUS, and 25% of survivors demonstrate long-term renal sequelae. Patients lost
to follow-up contribute to worse estimates in some studies. The severity of
acute illness, particularly central nervous system symptoms and the need for
initial dialysis, is strongly associated with a worse long-term prognosis.